This contribution examines the orthographic competence of Italian students, on the basis of their answers to questions related to orthography in the INVALSI tests of Italian. After a presentation of the structural characteristics of Italian orthography, we ask ourselves what kinds of variables affect the difficulty of the orthographic questions at different school levels; what kinds of strategies (phonological, lexical or morphosyntactic) may be activated by the students when answering these questions; if it is possible to identify a progression of difficulty in the questions administered at different school levels and, if yes, in what sense. We attempt to answer these questions by means of a quantitative (percentages of correct answers) and qualitative (peculiar characteristics) analysis of the orthographic questions administered within the tests of Italian, by taking into consideration the following variables: school level, the question intent, the question format, the correction criteria and the statistical elaboration of students’ answers.